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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/proc/root.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * proc root directory handling functions | |
7 | */ | |
8 | ||
7c0f6ba6 | 9 | #include <linux/uaccess.h> |
1da177e4 LT |
10 | |
11 | #include <linux/errno.h> | |
12 | #include <linux/time.h> | |
13 | #include <linux/proc_fs.h> | |
14 | #include <linux/stat.h> | |
1da177e4 | 15 | #include <linux/init.h> |
914e2637 | 16 | #include <linux/sched.h> |
03441a34 | 17 | #include <linux/sched/stat.h> |
1da177e4 LT |
18 | #include <linux/module.h> |
19 | #include <linux/bitops.h> | |
87a8ebd6 | 20 | #include <linux/user_namespace.h> |
f6c7a1f3 | 21 | #include <linux/mount.h> |
07543f5c | 22 | #include <linux/pid_namespace.h> |
97412950 | 23 | #include <linux/parser.h> |
5b825c3a | 24 | #include <linux/cred.h> |
1da177e4 | 25 | |
fee781e6 AB |
26 | #include "internal.h" |
27 | ||
97412950 | 28 | enum { |
0499680a | 29 | Opt_gid, Opt_hidepid, Opt_err, |
97412950 VK |
30 | }; |
31 | ||
32 | static const match_table_t tokens = { | |
0499680a VK |
33 | {Opt_hidepid, "hidepid=%u"}, |
34 | {Opt_gid, "gid=%u"}, | |
97412950 VK |
35 | {Opt_err, NULL}, |
36 | }; | |
37 | ||
e94591d0 | 38 | int proc_parse_options(char *options, struct pid_namespace *pid) |
97412950 VK |
39 | { |
40 | char *p; | |
41 | substring_t args[MAX_OPT_ARGS]; | |
0499680a | 42 | int option; |
97412950 VK |
43 | |
44 | if (!options) | |
45 | return 1; | |
46 | ||
47 | while ((p = strsep(&options, ",")) != NULL) { | |
48 | int token; | |
49 | if (!*p) | |
50 | continue; | |
51 | ||
9fb88442 | 52 | args[0].to = args[0].from = NULL; |
97412950 VK |
53 | token = match_token(p, tokens, args); |
54 | switch (token) { | |
0499680a VK |
55 | case Opt_gid: |
56 | if (match_int(&args[0], &option)) | |
57 | return 0; | |
dcb0f222 | 58 | pid->pid_gid = make_kgid(current_user_ns(), option); |
0499680a VK |
59 | break; |
60 | case Opt_hidepid: | |
61 | if (match_int(&args[0], &option)) | |
62 | return 0; | |
796f571b LW |
63 | if (option < HIDEPID_OFF || |
64 | option > HIDEPID_INVISIBLE) { | |
0499680a VK |
65 | pr_err("proc: hidepid value must be between 0 and 2.\n"); |
66 | return 0; | |
67 | } | |
68 | pid->hide_pid = option; | |
69 | break; | |
97412950 VK |
70 | default: |
71 | pr_err("proc: unrecognized mount option \"%s\" " | |
72 | "or missing value\n", p); | |
73 | return 0; | |
74 | } | |
75 | } | |
76 | ||
77 | return 1; | |
78 | } | |
79 | ||
80 | int proc_remount(struct super_block *sb, int *flags, char *data) | |
81 | { | |
82 | struct pid_namespace *pid = sb->s_fs_info; | |
02b9984d TT |
83 | |
84 | sync_filesystem(sb); | |
97412950 VK |
85 | return !proc_parse_options(data, pid); |
86 | } | |
87 | ||
aed1d84f AV |
88 | static struct dentry *proc_mount(struct file_system_type *fs_type, |
89 | int flags, const char *dev_name, void *data) | |
1da177e4 | 90 | { |
07543f5c | 91 | struct pid_namespace *ns; |
07543f5c | 92 | |
97412950 | 93 | if (flags & MS_KERNMOUNT) { |
e94591d0 EB |
94 | ns = data; |
95 | data = NULL; | |
97412950 | 96 | } else { |
17cf22c3 | 97 | ns = task_active_pid_ns(current); |
07543f5c PE |
98 | } |
99 | ||
e94591d0 | 100 | return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super); |
07543f5c PE |
101 | } |
102 | ||
103 | static void proc_kill_sb(struct super_block *sb) | |
104 | { | |
105 | struct pid_namespace *ns; | |
106 | ||
107 | ns = (struct pid_namespace *)sb->s_fs_info; | |
021ada7d AV |
108 | if (ns->proc_self) |
109 | dput(ns->proc_self); | |
0097875b EB |
110 | if (ns->proc_thread_self) |
111 | dput(ns->proc_thread_self); | |
07543f5c PE |
112 | kill_anon_super(sb); |
113 | put_pid_ns(ns); | |
1da177e4 LT |
114 | } |
115 | ||
c2319540 | 116 | static struct file_system_type proc_fs_type = { |
1da177e4 | 117 | .name = "proc", |
aed1d84f | 118 | .mount = proc_mount, |
07543f5c | 119 | .kill_sb = proc_kill_sb, |
8654df4e | 120 | .fs_flags = FS_USERNS_MOUNT, |
1da177e4 LT |
121 | }; |
122 | ||
1da177e4 LT |
123 | void __init proc_root_init(void) |
124 | { | |
5bcd7ff9 AD |
125 | int err; |
126 | ||
127 | proc_init_inodecache(); | |
1270dd8d | 128 | set_proc_pid_nlink(); |
1da177e4 LT |
129 | err = register_filesystem(&proc_fs_type); |
130 | if (err) | |
131 | return; | |
07543f5c | 132 | |
e656d8a6 | 133 | proc_self_init(); |
0097875b | 134 | proc_thread_self_init(); |
155134fe | 135 | proc_symlink("mounts", NULL, "self/mounts"); |
457c4cbc EB |
136 | |
137 | proc_net_init(); | |
1da177e4 LT |
138 | |
139 | #ifdef CONFIG_SYSVIPC | |
140 | proc_mkdir("sysvipc", NULL); | |
1da177e4 | 141 | #endif |
36a5aeb8 | 142 | proc_mkdir("fs", NULL); |
928b4d8c | 143 | proc_mkdir("driver", NULL); |
eb6d38d5 | 144 | proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */ |
1da177e4 LT |
145 | #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) |
146 | /* just give it a mountpoint */ | |
eb6d38d5 | 147 | proc_create_mount_point("openprom"); |
1da177e4 LT |
148 | #endif |
149 | proc_tty_init(); | |
9c37066d | 150 | proc_mkdir("bus", NULL); |
77b14db5 | 151 | proc_sys_init(); |
1da177e4 LT |
152 | } |
153 | ||
a528d35e DH |
154 | static int proc_root_getattr(const struct path *path, struct kstat *stat, |
155 | u32 request_mask, unsigned int query_flags) | |
1da177e4 | 156 | { |
a528d35e | 157 | generic_fillattr(d_inode(path->dentry), stat); |
76b6159b AV |
158 | stat->nlink = proc_root.nlink + nr_processes(); |
159 | return 0; | |
160 | } | |
1da177e4 | 161 | |
00cd8dd3 | 162 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) |
76b6159b | 163 | { |
335eb531 | 164 | if (!proc_pid_lookup(dir, dentry, flags)) |
1da177e4 | 165 | return NULL; |
1da177e4 | 166 | |
335eb531 | 167 | return proc_lookup(dir, dentry, flags); |
1da177e4 LT |
168 | } |
169 | ||
f0c3b509 | 170 | static int proc_root_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 171 | { |
f0c3b509 | 172 | if (ctx->pos < FIRST_PROCESS_ENTRY) { |
94fc5d9d RG |
173 | int error = proc_readdir(file, ctx); |
174 | if (unlikely(error <= 0)) | |
175 | return error; | |
f0c3b509 | 176 | ctx->pos = FIRST_PROCESS_ENTRY; |
1da177e4 | 177 | } |
1da177e4 | 178 | |
f0c3b509 | 179 | return proc_pid_readdir(file, ctx); |
1da177e4 LT |
180 | } |
181 | ||
182 | /* | |
183 | * The root /proc directory is special, as it has the | |
184 | * <pid> directories. Thus we don't use the generic | |
185 | * directory handling functions for that.. | |
186 | */ | |
00977a59 | 187 | static const struct file_operations proc_root_operations = { |
1da177e4 | 188 | .read = generic_read_dir, |
f50752ea AV |
189 | .iterate_shared = proc_root_readdir, |
190 | .llseek = generic_file_llseek, | |
1da177e4 LT |
191 | }; |
192 | ||
193 | /* | |
194 | * proc root can do almost nothing.. | |
195 | */ | |
c5ef1c42 | 196 | static const struct inode_operations proc_root_inode_operations = { |
1da177e4 | 197 | .lookup = proc_root_lookup, |
76b6159b | 198 | .getattr = proc_root_getattr, |
1da177e4 LT |
199 | }; |
200 | ||
201 | /* | |
202 | * This is the root "inode" in the /proc tree.. | |
203 | */ | |
204 | struct proc_dir_entry proc_root = { | |
205 | .low_ino = PROC_ROOT_INO, | |
206 | .namelen = 5, | |
1da177e4 LT |
207 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
208 | .nlink = 2, | |
5a622f2d | 209 | .count = ATOMIC_INIT(1), |
1da177e4 LT |
210 | .proc_iops = &proc_root_inode_operations, |
211 | .proc_fops = &proc_root_operations, | |
212 | .parent = &proc_root, | |
710585d4 | 213 | .subdir = RB_ROOT, |
09570f91 | 214 | .name = "/proc", |
1da177e4 LT |
215 | }; |
216 | ||
6f4e6433 PE |
217 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
218 | { | |
219 | struct vfsmount *mnt; | |
220 | ||
221 | mnt = kern_mount_data(&proc_fs_type, ns); | |
222 | if (IS_ERR(mnt)) | |
223 | return PTR_ERR(mnt); | |
224 | ||
579441a3 | 225 | ns->proc_mnt = mnt; |
6f4e6433 PE |
226 | return 0; |
227 | } | |
228 | ||
229 | void pid_ns_release_proc(struct pid_namespace *ns) | |
230 | { | |
905ad269 | 231 | kern_unmount(ns->proc_mnt); |
6f4e6433 | 232 | } |